find the ip address of the client in an ssh session

Question

I have a script that is to be run by a person that logs in to the server with ssh.

Is there a way to find out automatically what ip is the user connecting from.

Of course, I could ask the user (it is a tool for programmers, so no problem with that), but it would be cooler if I just found out.

Answer 1

Usually there is a log entry in /var/log/messages (or similar, depending on your OS) which you could grep with the username.

Answer 2

Check if there is an environment variable called:

SSH_CLIENT

OR

SSH_CONNECTION

(or any other environment variables) which gets set when the user logs in. Then process it using the user login script.

Answer 3

Assuming he opens an interactive session (i. e. allocates a pseudo terminal) and you have access to stdin , you can call an ioctl on that device to get the device number (/dev/pts/4711) and try to find that one in /var/run/utmp (where there will also be the username and the ip the connection originated from).

Answer 4

You could use the command:

server:~# pinky

that will give to you somehting like this:

Login      Name                 TTY    Idle   When                 Where 

root       root                 pts/0         2009-06-15 13:41     192.168.1.133